Bangladesh police have arrested three managers of a factory where a blaze killed 110 people at the weekend.

Dhaka police said the three mid-level managers were charged after they told panicked workers of Tazreen Fashion they had nothing to worry about when the fire started.

"Survivors told us that they did not allow the workers to escape the fire, saying that it was a routine fire drill. There are also allegations that they even padlocked doors," police chief Habibur Rahman said.

Survivors and witnesses told the AFP new agency how workers, most of them women, tried to escape the burning factory, which supplied clothes to international brands including Walmart, European chain C&A and the Hong Kong-based Li & Fung company.

Two government inquiries have already been set up to try to establish the cause of the fire, the worst factory blaze to hit Bangladesh's garment industry, which employs three million and is the mainstay of the economy.

The US-based Institute for Global Labour and Human Rights said the owners of the factory were criminally negligent.

"Some of the workers we were talking to on the fifth floor, they actually made it down to the third floor, where this production manager slammed the gate shut and locked it from the outside and wouldn't let them go down," director Charles Kernaghan told Radio Australia's Connect Asia program.

"And so, they were just trapped. This is a criminal action, they were trapped and that is why so many of these workers were killed, a minimum of 112 workers were killed, it's probably going to go much higher."

The American retailer Walmart has cut its ties with the factory, which it says was carrying out subcontracted work on behalf of its suppliers, but without Walmart's permission.